Utility companies generally must read their meters in order to bill customers for the resources consumed by the customers. In the past, a meter-reader—a person—may have needed to visit each home and business and read the meter. More recently, some utility meter manufacturers have equipped utility meters with automatic meter reader systems (“AMR”). The AMR typically designates the utility meter data format as well as the communications protocol used in transmitting the data. An example legacy AMR system may be Itron Encoder-Receiver-Transmitter (“ERT”). Frequently, the legacy AMR system wirelessly transmits the meter reading, but the range of the transmission is limited. The limited range often requires an electronic meter-reader—a device—to be close to the meter to get a reading, although generally the operator may not have to walk right up to the meter. This means that the meter-reader may have to drive or walk by every meter to collect the data. In some instances, however, the meter-reader will still need to approach the meter even though the reading is accomplished electronically. Collecting the meter data in this way is time consuming and often only permits infrequent meter readings, such as once a month.
The AMR of utility meters is generally designated by the utility meter manufacturer. Often, the AMR of a given utility meter is not compatible with a smart energy (“SE”) network deployed at the site of the utility meter. Retrofitting existing meters to communicate with the SE network may be expensive and require tremendous effort while replacing otherwise satisfactory utility meters to being even more expensive if they cannot be retrofitted.
SE devices and networks have been deployed in homes and businesses as utilities and consumers attempt to better understand and control energy use. SE networks are typically a collection of monitoring, control, and reporting devices located, for example, in a home or a business. Typical SE devices may include, for example, thermostats and water, gas, and electric utility meters. The SE devices generally implement one or more communications protocols to communicate with each other and ultimately the utility or consumer. SE devices also typically conform to a standard reporting format based on the device. For example, all SE gas meters in a given SE network may produce data in a common format. Some SE networks may interface with an automated metering infrastructure (“AMI”) network of a utility company to record data from SE meters. ZigBee Alliance Smart Energy is an example SE network and set of SE device standards.
The SE devices on the SE network may be interconnected in various ways but are often interconnected, at least in part, by a mesh network. The mesh network may be a wireless personal area network (“WPAN”). An example of a WPAN is a ZigBee wireless network. A ZigBee wireless network implements the IEEE 802.15.4 communication protocol standard for WPANs. WPAN node devices are typically low power [e.g., 1 milliwatt (mW) to 250 mW] and have lower data rates [e.g., 250 kilobits per second (kbps)] than node devices for other networks.
WPAN node devices are typically powered by either an external power brick requiring a power cord or they are powered by batteries. WPAN node devices having an external power brick are bulky and may make a WPAN less convenient to implement. Such WPAN node devices often require additional mounting hardware or a special installation which can be expensive and cumbersome.
A WPAN implemented using battery powered node devices tries to conserve power and extend the life of the batteries of the individual nodes. To extend the battery life of battery-powered router nodes in WPAN applications, the nodes may be required to enter a very low power mode for most of the time that the network is operating, which results in decreased throughput. Periods of high network traffic can quickly drain batteries. Furthermore, when batteries reach the end of their life, battery powered nodes require more maintenance and pose a higher risk of network failure.